Figure 4. Complement inhibition by MASP C-terminal peptides.

Cr⁵¹ labeled Epimastigote forms were treated with 10% heat inactivated sera from chagasic patients diagnosed as gastrointestinal, cardiopathic or asymptomatic. After incubation with 1/18 dilution human complement (CH₅₀) and 1 μg/100 μl of each peptide (C1–C7) at 37 °C for 1 h. Pooled sera from chagasic patients without inactivation was used as positive control and a pool of inactivate sera without the supplement of complement as a negative control.The data percentage of Cr⁵¹ specific release was calculated by the formula %IC = (LspC − Lsp/Lsc) × 100, where %IC is the percentage of complement inhibition, Lsp the specific liberation of samples, LspC the specific liberation of positive control samples and Lspc the specific liberation on negative control samples.